Wheel brake mechanism



Feb. 15, 938. 1 V. CRlCHTON 2,108,401

WHEEL BRAKE MECHANI SM Filed 00h18, 1936 5 Sheets-Sheet 1 ZI-2G21.

- ATTORNEYS;

Feb.. 15, T938..- J4 v. cRlcHToN y I 210,491

WHEEL. BRAKE MECHANISM Filed oct. s, '195ey 3 sheets-sheet 2 y Ajig y BY WITNESSS INVENTOR;

Feb. l5, w3.,

WHEEL BRAKE MECHANISM J.v v. CRICHTON Filed Oct. 8, 1956 o iI 'Il M65 i IZ 3 Sheets-Sheet 3 INVENTR:v

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Patented Feb. 15, 1938 l `UNITED STATES FATENT DFFlE WHEEL BRAKE MECHANISM James V. Crichton, Philadelphia, Pa., assigner of one-half to Karl Salberg, Philadelphia, Pa.

Application October 8, 1936, Serial No. 104,602

9 Claims.

This invention relates to wheel brakes useful in connection with automobiles and other vehicles, elevators and other machinerywhere quick and effective Wheel stoppage is desired or necessary.

The chief aim of my invention is to make it possible to utilize toothed gearing in securing effective wheel brake action with exertion of a minimum of manual effort. This desideratum I realize in practice, as hereinafter more fully eX- plained, through provision of a simple and reliable brake mechanism wherein a planetary gear unit, including a series of circumferentially-arranged gear pinions on a hub member to which the wheel is secured and a pair of contiguouslyplaced intermeshing gear elements concentric with the wheel axis, bodily rotates with the wheel normally; and wherein, when the brake is to be applied, the two gear elements are rst stopped from rotating with the intermeshing pinions m11- ing around them, and then subjected to rotational torsion in opposite directions to restrain and finally check rotation of the pinions.

' Other objects and attendant advantageswill appear Vfrom the following detailed description of the attached drawings, wherein Fig. I shows, in axial section, one of the drive wheels of an automobile embodying my improved mechanism, viewed as indicated by the arrows I--I in Figs. II and III. d

Fig. II is a detail sectional view taken as indicated by the arrows II-II in Fig. I, with the control means for the brake mechanism diagrammatically shown.

Fig. III is a detail sectional view taken as indicated by the arrows III--III in Fig. I.

Fig. IV isa fragmentary view corresponding to Fig. II, showing a modified detail; and

Fig. V is a fragmentary sectional view corresponding to Fig. I showing an alternative embodiment of my invention'.

With more specic reference first to Figs. I-III of these illustrations, the wheel designated comprehensively by the numeral l is of well known ,L5 construction and removably secured by bolts 2 to a hub member 3. As' shown, the hub member 3 is mounted to revolve freely, with interposition of anti-friction rollers ll, about the axial boss 5 of a central bearing member t through which 50 the section 'l of the drive shaft of the automobile extends, said hub member being keyed as at 8 to the outer tapered end of said shaft section l' and secured by a retaining nut I0 after more or less common practice. To the tubular housing il surrounding the shaft section 'l is riveted (Cil. 18S- 152) the half component I2 of a coaxial cylindrical oil-tight casing i3 which encloses the planetary gearing and other parts of the brake mechanism, the other half oi said casing being indicated at I4. As shown in Fig. I, the bearing member 5 "15 is secured to the casing component l2 by screw bolts I5. l

The wheel hub membei` 3, it will be noted, consists of two separable sections il and i8 which are rigidly connected by a plurality of screwflO bolts, whereof one is indicated at i9 in Fig. I, and which are respectively formed with integral concentric disk flanges 2l), 2|. In the interval between thedisk flanges 2D, 2l is a circumferentially-arranged series of spur pinions 22 which .115 are keyed as at 23 to individual shafts 25 journaled for independent rotation in bearing apertures allorded by said flanges. Mounted with capacityfor independent rotation about the peripheries of the disk flanges 20, 2l are a pain-20 of contiguously placed rings 23, 2l which meet in a multiple annular lap tongue and groove sealing juncture 28 designed to prevent escape of lubricating grease from within the hollow 29 of the hub member 5. Internally, the rings 23, 21.125 are respectively provided with gear teeth 29, for meshing engagement with the several pinions 22, and externally, with oppositely-iaced ratchet teeth 3l, 32 which are adapted to be engaged respectively by pawl elements 33 and 34 havingggo correspondingly faced teeth for a purpose later on explained.V As shown in Figs. I and III, the pawl elements 33, 3.4i are respectively supported by arms 35, 36 aixed to shafts 3l, 38 which extend outward through suitable bearing apertures :,135

in the casing component l2. To the protruding ends of the shafts 3l, 38, see Fig. II, are affixed bell cranks`39, 43. A spring il connecting the arms 39a, 4ta of the bell cranks 33, 4U serves to keep the pawl members 33, 33 normally `rer-ga() tracted clear of the ratchet teeth 3l and 32 on the two gear rings 26 and 21. The longer arms 33h, @b of the bell cranks 39, 40 are'coupled,

by means of links 52, and 43 respectively, with the piston rods dit, of hydraulic actuating cyl- :,345 inders t5, lil bolted fast to the back of the casing component l2.

Surrounding the gear ringsnli, 2 in the interval between their ratchet teeth 3l, 32 is a contractible brake band 5D with a renewable lin- .50 ing 5l, said brake band being split and having upwardly extending ear lugs 52, and 53 secured to its ends, which lugs, it will be noted from Fig. III, are `a-pertured for passage of an actuating vshaft 55. At one end, the shaft 55 has journaledgl55 support in a boss 56 on an upward extension 51 of the casing component I 2, and at its other end Within the hollow of a bearing sleeve 58 which is threadedly engaged in the upward extension of the casing, and which forms an adjustable abutment for the ear 52 on the brake band. At its outer end, the sleeve 58 is provided with a polygonal head 59 which permits the use of a wrench in adjusting it; and associated with the sleeve is a jam nut 6D for iixing it in adjusted positions. The ear 53 of the brake band 50 has an integrally-formed cam boss 6I which is adapted to react with a cam collar 62 pinned to the actuating shaft 55 within the upward extension 51 of the casing I3, the cam surfaces of said boss and said collar being maintained in engagement by the inherent springiness of. the brake band. 'I'o the outer end of the shaft 55 beyond the bearing 56 is secured an arm 63 arranged to be operated by a :duid actuated cylinder 64. Access may be had to the interior of the casing I3 upon removal of a cover 65 secured by screws 66 over the opening at the top of the upward projection 51 of the casing component I2.

The control means for the brake mechanism may be as diagrammatically shown inf Fig. II, comprising a pedal lever 61 with a pair of arms 68, 69 for respectively actuating the pistons 10, 1I of master hydraulic cylinders 12, 13 whereof the first is connected by a pipe 16 with the brake band operating cylinders 64 and the second by a branched pipe 15 with the two pawl actuating cylinders 46 and 41. As will be presently apparent, it is essential to the propel` operation of the brake mechanism that the band 56 be actuated prior to engagement of the gear rings 26, 21 by the pawl members 33, 34. The arms 68 and 69 of the pedal lever 61 are accordingly s0 spaced angularly that the piston 1I) of the master cylinder 12 is operated somewhat ahead of the piston 1I of the master cylinder 13. In order that the proper period of delay may be accurately determined, the arm 68 of the pedal lever 61 is provided with an adjustable stud screw 16 which directly engages the piston 10 of the master cylinder 12.

The operation of the brake mechanism is as follows: Normally, with the pawl members 33 and 34 retracted and the brake band 56 relaxed, the planetary gearing including 'the rings 26, 21 and the pinions 22, revolves bodily as a unit with the wheel I. Upon depression of the foot pedal lever 61, the piston 1S of the master cylinder 12 is first operated, with attendant actuation, in turn, of the cylinder 64 and contraction of the brake band 5I] to stop andi hold the two gear rings 26, 21 against rotation so that the pinions 22 are obliged to roll around them. As the control pedal 61 is further depressed and the piston 1I of the master cylinder 13 actuated, pressure fluid is forced into the cylinders 46, 41 with the result that the pawl members 33, 34 are moved into engagement with the ratchet teeth 3l, 32 on the rings 26, 21, and impart rotary torsional strain in opposite directions, to said rings. A binding action is thus induced between the gear teeth of the rings 25, 21 and the pinions 22 by which the wheel I is quickly decelerated and iinally stopped altogether, the rate of retardation being directly proportional to the pressure exerted upon the control pedal 61.

In practice, the band 50 is adjusted that the pressure exerted upon the rings 2B, 21 is relatively lightwjust suilicient to prevent them from rotating-so that said rings can be influenced by the pawl members 33, 34 in the manner described.

In the alternative embodiment of my invention shown in Fig. IV, a single double-acting hydraulic cylinder 46c with two pistons is employed instead of two separate cylinders to actuate the pawl members 33 and 34. Moreover, in the modification, in lieu of bell cranks, arms 39e and 40e are secured to the shafts 31 and 38 to which the arms 35 and 36 of the pawl members are attached. As shown, the arms 39e, 46c bear upon the ends of the pistons in the hydraulic cylinder 46c; and a spring 4Ic connecting said arms tends to keep the pawl members normally out of engagement with the ratchet teeth of the two gear rings.

In the alternative embodiment of my invention illustrated in Fig. V, a brake band is dispensed with, and the rings 26, 21 provided with bevel gear teeth Sid, 32d instead of ratchet teeth. Meshing with the bevel gear teeth 3Id, 32d is a bevel pinion 33d on a shaft 31d which extends through a bearing boss on a casing component I2 and to which is secured at the outer end, an actuating arm 39d. As a result of this alternative arrangement, the rings 26 and 21 are normally held stationary by the bevel pinion 33d with the spur pinions 22 rolling on the internal gear teeth 29, 3D of said rings. Brake application is here effected by slight turning of the actuating lever 39d in one direction or the other, with resultant impartation of rotative torsion in oppo site directions to the gear rings 26, 21 as in the rst described embodiment of my invention.

While, for the purposes of exemplication I have shown and described my invention in assov:5.

ciation with a vehicle wheel, it can obviously be employed in other connections with attainment of advantages equal in all respects to those pointed out hereinbefore.

Having thus described my invention, I claim:

1. Wheel brake mechanism comprising a plurality of rotatably-free gear pinions circumferentially arranged about the wheel axis and carried by the Wheel; a pair of independently supported juxtaposed toothed gear elements concentric with the wheel axis and meshing with the several pinions; and means operative to exert rotary torque in opposite directions upon the two gear elements in effecting the wheel braking.

2. Wheel brake mechanism comprising a plurality of gear pinions circumferentially arranged about the wheel axis; a hub member on the wheel supporting the pinions with capacity for independent rotation; a pair of juxtaposed toothed gear elements concentric with the wheel axis and meshing with the several pinions, said vgear elements being normally free to revolve with the wheel; and control means operative to first stop and hold the gear elements from rotating and to thereafter, with the pinions rolling around said gear elements, to exert rotary torsion in opposite directions upon the latter.

3. Wheel brake mechanism according to claim l, wherein the intermeslL'ng pinions and gear elements are enclosed in an oil-tight casing, and the gear elements controlled by connections extending into the interior of the housing.

4. Wheel brake mechanism comprising a plurality of gear pinions circumerentially arranged about the wheel axis; a hub member on the wheel supporting the pinions with capacity for independent rotation; a pair of juxtaposed gear rings concentric with the wheel axis and having internal teeth in mesh with the several pinions, said rings being normally free to revolve with the wheel; and control means operative to rst stop and hold the two rings from rotating, and to thereafter, with the pinions rolling on the teeth around said rings, exert rotary torque upon the latter in opposite directions.

5. Wheel b-rake mechanism comprising a plurality of gear pinions circumferentially arranged about the wheel axis; a hub member on the wheel supporting the pinions with capacity for independent rotation; a pair of juxtaposed rings concentric` with the wheel axis and having internal teeth in mesh with the several pinions, said rings being normally free to revolve with the wheel; a brake band common to the two gear rings; and control means operative to rst contract the brake band and to thereby stop the two rings from rotating, and to thereafter, with the pinions rolling around the teeth of said rings, exert rotary torque upon the latter in opposite directions.

6. Wheel brake mechanism comprising a plurality of gear pinions circumferentially arranged about the wheel axis;l a hub member on the wheel supporting the pinions'with capacity for independent rotation; a pair of juxtaposed rings concentric With the Wheel axis and having internal teeth in mesh with the several pinions, said rings being normally free to revolve with the Wheel; and also having oppositely-faced external ratchet! teeth respectively? normally retracted pawl members respectively associated with said rings; and control means operative to first stop and hold the two rings from rotating, and to thereafter, with the pinions rolling around the gear teeth of said rings, movevthe pawl members concurrently into engagement with the ratchet teeth on the rings and thereby exert rotary torque upon the latter in opposite directions.

'7. Wheelbrake mechanism comprising a plurality of gear pinions circumferentially arranged about the wheel axis; a hub member on the wheel supporting the pinions with capacity for independent rotation; a pair of juxtaposed rings concentric With the Wheel axis and having inte-rnal Y gear teeth in mesh with the several pinions, said rings being normally free to revolve with the wheel and also having oppositely faced external ratchet teeth respectively; an oil-tight casing enclosing the `hub member andthe rings; pawl members respectively associated with the rings within the casing, said pawl members bein-g secured to shafts extending through the wall of the casing; actuating arms on the protruding ends of said shafts; hydraulic cylinder means for actuating said arms; and control means operative to rst stop and hold the two rings from rotating, and to thereafter, with the pinions rolling around the gear teeth of said rings, move the arms aforesaid concurrently tobring the pawl members into engagement with the ratchet teeth on the rings and exert rotary torque upon the latter in opposite directions.

8. Wheel brake mechanism comp-rising arplurality of gear pinions circumferentially arranged about the wheel axis; a hub member on the wheel supporting the Vpinions for independent rotation; a pair of juxtapositioned rings concentric with the Wheel axis and having internal teeth 1n mesh With the several pinions, said rings being normally free to revolve with the wheel and also having oppositely face-d external ratchet teeth respectively; a brake band common to the two gear tively associated with the rings; a casing enclosing the Wheel hubfmember, the gear rings, the brake band, and the pawl members; actuating connections for the brake band and for the pawl members extending to the exterior of the vcasing; and control meansv operative to first contract the brake band to stop and hold the rings from rotation, and to thereafter, with the pinions rollin-g around the gear teeth of said rings, actuate the pawl members concurrently to bring them into engagement with the ratchet teeth on the rings: and exert rotary torque to the latter in opposite directions. V Y

9. Wheel brake mechanism comprising a plurality of rotatably `free gear pinions circumferentiallyarranged about the Wheel axis and carlried by the wheel; a pair of independently supported juxtapositioned gear rings concentric with the Wheel axis, said rings having internal teeth in mesh with the several pinions, and opposingly arranged external peripheral bevel gear teeth; an intermeshing bevel pinion common to the two rings and preventing their rotation normally; and means whereby the bevel pinion may be actuated to exert rotary torque in opposite directions upon the gear rings in effecting the wheel braking. JAMES V. CRICHTON.

frings; normally retracted pawl members respec- Y 

